1. Field of the Invention
This invention relates to a compound transmission of the splitter type and more particularly to a compound splitter type transmission having a selectively engagable and disengagable extended range section for providing increased ratio coverage, especially in the low speed ratios, and/or allowing the use of an auxiliary section countershaft PTO.
Preferably, the extended range section is engagable to provide an additional gear reduction only in the low speed ratio of the main transmission section and is utilized with the same, or substantially the same, main and auxiliary transmission section components as a standard (non-extended range) compound splitter type transmission.
2. Description of the Prior Art
Compound change gear transmissions comprising a multiple speed main transmission section connected in series with one or more multiple speed auxiliary transmission sections are well known in the prior art. Such transmissions are usually utilized with heavy duty vehicles and are of the splitter type or the range type or a combination thereof, as may be seen by reference to U.S. Pat. Nos. 3,105, 648,546; 3,799,002; 3,921,469; 3,924,484; 2,932,988 and 3,229,551, the disclosures of which are all hereby incorporated by reference.
The present invention is particularly well suited for use in connection with a compound splitter type change gear transmission of the semi-blocked type as disclosed in European Patent No. 0071353, the disclosure of which is hereby incorporated by reference. Briefly, such a semi-blocked transmission is sold by the Assignee of this invention, Eaton Corporation, and its British subsidiary, Eaton Limited, under the trademark "Twin-Splitter" and comprises a multiple speed main transmission section connected in series with a blocked splitter type auxiliary transmission section.
While semi-blocked splitter type compound change gear transmissions are very well received, there has been, for certain applications, a need for extended low speed ratio coverage and/or for structure allowing the use of an auxiliary section countershaft PTO (i.e. "power take off" device).